Polygonal speaker enclosure



FIG. 1 is a front elevation of a polygonal speaker enclosure showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a side elevation thereof;

FIG. 4 is a rear elevation thereof; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a polygonal speaker enclosure, substantially as shown and described. 